You can use your timeline to update your registration open date, your registration close date, start times for each distance you offer, as well as the actual date for your individual distances if they are happening across multiple days.

To edit the registration close date on your timeline, navigate to event setup, click edit event from your admin tools.

Then click the timeline tab:

Scroll to the ‘critical dates’ section, and click the pencil/edit link next to the registration close date: